Accumulate TOWER Coins and complete the specified requirements to increase your Crime Rating.
There are 5 Crime Ratings in total. As your rating goes up, carjacking becomes more challenging-but you'll also get bigger drop quantity bonuses, higher Bounty Order spawn rates, and better Bounty Orders, which means way better loot in your pocket.
Upon reaching 3 Stars, you'll be able to access TOWER Co. Central Vault to take on much more difficult and rewarding challenges.
Carjack drops are not affected by "drop quantity bonuses for certain types of items".